Adverse drug events (ADEs) are the most clinically significant and costly medication-related problems in nursing homes (NH) and are associated with an estimated 93,000 deaths a year and in as much as $4 billion of excess healthcare expenditures. Current ADE detection and management strategies that rely on pharmacist retrospective chart reviews (i.e., usual care) are inadequate. Active medication monitoring systems are recommended by many safety organizations as an alternative to detect and manage ADEs. These systems have been shown to be less expensive, faster, and identify ADEs not normally detected by clinicians in the hospital setting. We developed and pilot-tested an active medication monitoring system for use in a single NH, where it was shown to detect ADEs with a high degree of accuracy and at a rate of nearly 2.5 times that of usual care. The long-term objective of our proposed research is to improve patient safety with respect to medications in NHs. The short-term objectives or specific aims of our proposed research are to determine if NH patients managed by physicians who receive active medication monitoring alerts have more ADEs detected, have a faster ADE management response time, and can result in more cost-savings from a societal perspective compared to usual care. To accomplish these aims, we will conduct a cluster randomized controlled trial among 86 NH physicians working in one of 4 NHs in Southwestern PA for a period of 12 months. Our hypotheses are that NH patients managed by physicians who receive active medication monitoring alerts will have more ADEs detected, will have a faster ADE management response time, and will result in cost-savings from a societal perspective compared to usual care. This application by an early stage investigator is responsive to PA-09- 070 AHRQ Health Services Research Projects and several of its research portfolio priority areas (health information technology, patient safety, and value) by addressing how medication management systems can be used to improve the quality and safety of medication management, as well as improve healthcare decision making. This study represents the first large, well-controlled, comprehensive examination of an active medication monitoring system in the NH.